code review 135110044: go/token: implement PositionFor accessors

go/token: implement PositionFor accessors

Package addition.

PositionFor permits access to both, positions
adjusted by //line comments (like the Position
accessors), and unadjusted "raw" positions
unaffected by //line comments.

Raw positions are required for correct formatting
of source code via go/printer which until now had
to manually fix adjusted positions.

Fixes issue 7702.

[gri, 2014-08-28 18:42:28]

Hello adonovan@google.com (cc: golang-codereviews@googlegroups.com),

I'd like you to review this change to
https://code.google.com/p/go/

[adonovan, 2014-08-28 19:06:01]

LGTM

I've needed this function in the past.

https://codereview.appspot.com/135110044/diff/60001/src/pkg/go/token/position.go
File src/pkg/go/token/position.go (right):

https://codereview.appspot.com/135110044/diff/60001/src/pkg/go/token/position...
src/pkg/go/token/position.go:264: // unpack returns the filename, and line and
column number for a file offset.
"filename and"

https://codereview.appspot.com/135110044/diff/60001/src/pkg/go/token/position...
File src/pkg/go/token/position_test.go (right):

https://codereview.appspot.com/135110044/diff/60001/src/pkg/go/token/position...
src/pkg/go/token/position_test.go:262: checkPos(t, "1) PositionFor unadjusted",
got1, want)
"1. PositionFor unadjusted" etc
The unbalanced rparen really threw me at first!

https://codereview.appspot.com/135110044/diff/60001/src/pkg/go/token/position...
src/pkg/go/token/position_test.go:284: // manually compute wanted fileame and
line
'filename'

[gri, 2014-08-28 19:15:51]

https://codereview.appspot.com/135110044/diff/60001/src/pkg/go/token/position.go
File src/pkg/go/token/position.go (right):

https://codereview.appspot.com/135110044/diff/60001/src/pkg/go/token/position...
src/pkg/go/token/position.go:264: // unpack returns the filename, and line and
column number for a file offset.
On 2014/08/28 19:06:01, adonovan wrote:
> "filename and"

Done.

https://codereview.appspot.com/135110044/diff/60001/src/pkg/go/token/position...
File src/pkg/go/token/position_test.go (right):

https://codereview.appspot.com/135110044/diff/60001/src/pkg/go/token/position...
src/pkg/go/token/position_test.go:262: checkPos(t, "1) PositionFor unadjusted",
got1, want)
On 2014/08/28 19:06:01, adonovan wrote:
> "1. PositionFor unadjusted" etc
> The unbalanced rparen really threw me at first!

(not problem if you have syntax coloring :-)

fixed

https://codereview.appspot.com/135110044/diff/60001/src/pkg/go/token/position...
src/pkg/go/token/position_test.go:284: // manually compute wanted fileame and
line
On 2014/08/28 19:06:01, adonovan wrote:
> 'filename'

Done.

[gri, 2014-08-28 19:16:09]

*** Submitted as https://code.google.com/p/go/source/detail?r=401c7c5a77d0 ***

go/token: implement PositionFor accessors

Package addition.

PositionFor permits access to both, positions
adjusted by //line comments (like the Position
accessors), and unadjusted "raw" positions
unaffected by //line comments.

Raw positions are required for correct formatting
of source code via go/printer which until now had
to manually fix adjusted positions.

Fixes issue 7702.

LGTM=adonovan
R=adonovan
CC=golang-codereviews
https://codereview.appspot.com/135110044

[gobot, 2014-08-28 19:47:35]

This CL appears to have broken the freebsd-amd64-race builder.
See http://build.golang.org/log/8058a90a9935418e7826690f1626483f3ceb99a0